P0128 Code

For the past several weeks, I've had an intermittent check engine light. Sometimes it stays off for a couple of days, but now it seems to come on within a few minutes on each start-up. Scan say P0128.

My looking about on the forums suggests coolant temperature sensor is not working properly. Have not driven far enough to check on fuel economy, but start-up, accel, and normal running do not seem to be affected.

Have to go on a 2,000-mile drive next week. It's cold and I don't have garage space. Should I swap this out before I go? Is it the little sensor on the drivers side end of the motor?

Thanks in advance.

JohnD

It could be the sensor or the thermostat. I get this code sometimes using a zerostart heater, since the coolant temp drops quickly after startup from the heater core cooling it down.

cvalentine said:

It could be the sensor or the thermostat. I get this code sometimes using a zerostart heater, since the coolant temp drops quickly after startup from the heater core cooling it down.

Click to expand...

I have a FrostHeater that I used to use when I had to leave for work at 6 AM. Have not needed it lately but this code has come up in the absence of pre-heater usage. "Idiot gauge" on the dash typically responds to 190 by the book (although seems often to have no relationship to what the coolant is doing).

Sounds like swapping it out before your trip might not be a bad idea, just make sure you have a spare plastic clip on hand.